Internal-combustion engine



I. 0. CASADAY. INTERNAL COMBUSTION ENGINE. APPLICATION FILED MAR- I2II9I 9.

2 SHEETSSHEET l.

- AVE/V7272 J rraawsn (7&77205 Q "Gsaday UNITED STATES PATENT OFFICE.

- JAMES O. CASAIDAY, OF SOUTH BEND, INDIANA.

' ETERNAL-COMBUSTION ENGINE.

Application filed March 12, 1919. Serial No. 282,236.

and useful Improvements in Internal-Combustion Engines, of which thefollowing is a specification. r

This invention relates to an improvement in internal combustion enginesof that type wherein the cylinders are arranged in coupled or associatedpairs, with one cylinder of a pair utilized as a compressioncylinder forthe charge, and the other cylinder of the pair serving as the firing'orpower cylinder.

In engines of this type, as heretofore generally proposed, it hasbeencustomary to transfer the charge from the compression cylinder to thefiring cylinder before either of such cylinders has reached the extremelimit of its stroke. This tends to prevent a complete scavenging of thefiring cylinder, and compels the piston of such firing cylinder to aidin the compression of the charge.

The present invention arranges the cylindersv and pistons of therespective pairs, so that the piston of the firing cylinder is inadvance of the piston of the compression cylinder, so that the chargefrom the compression cylinder is delivered to the firing cylinder duringthe initial movement of the. piston of the firing cylinder on the powerstroke. This permits a full scavenging stroke of the firing piston,delivers the charge under the full compression stroke of the compressionpiston, and fires the charge when the crank of the firing piston is atthe most effective point for leverage action. The invention is shown inthe preferred form in the accompanying drawings, in

Figure 1 is a vertical sectional view illustrating the invention.

Fig. 2 is a plan view of the samef Fig. 3 is a diagrammatic viewillustrating the relative positions of the pistons and cranks at firingpoint. 7

Fig. 4 is a similar view showing the position of the crank of the firingpiston at time of firing.

The improved construction is here shown as including the cylinders ofone pair only,

it being understood that any desired battery of cylinders maybe used,when arranged in associated pairs as described.

The firing cylinder 1 and associated com Specification of LettersPatent.-

Patented Mar. 22, 1921.

pression cylinder 2 are. of any usual type or construction, andsubstantiall of equal cubical. area. A piston 3, hereina ter termed thepower piston is arranged in the cylinder 1, while a similar piston 4,hereinafter termed the compression piston, is arranged in thecompression cylinder. The power piston 1s given a lead over thecompression piston, as will be clear from Figs. 3 and 4, in that thecrank 5 of the connecting rod 6 of the power piston is arranged inadvance of the crank 7 of the connecting rod 8 of the compressionpiston. This degree of advance may vary in accordance with desiredconditions, but the particular feature here involved is that the powerpiston will have reached the end of its stroke and reached a polntapproximately 45 over center be fore the firing occurs, at which timethe compression piston will have completed its stroke.

An inlet valve 9, involving any usual or preferred type of inlet valvestructure, is arranged at the upper end and to one side of the center ofthe'compression cylinder, this valve;being held closed by the usualspring,

as 10, and being automaticallyopened by a the suction of the compressionpiston in its down stroke. A similar exhaust valve 11 is arranged at thetop of the firing cylinder, this valve being also of any usual orpreferred type, normally held closed by a spring 12. Any desired means(not shown) may be employed and properly timed to open and holdopen theexhaust valve to allow practically a full up stroke of the powerpisranged at an angle to a line between the inlet and exhaust valveswith one end thereof integral with the exhaust valve, and the oppositeend to one side of and spaced from the inlet valve. The end of thecasing next the inlet valve is open and a valve bushing 14.- is slidablyfitted therein, a cap 15 removably closing and sealing'the openend ofthe casing..' The bushing 14. has an inward projection 16, formed toslidably receive a valve rod 17, terminally carrying a valve 18,

. adapted to cooperatewith a seat 19 formed at the end of the bushing.The valve opens toward the firing cylinder, and the casing 13 is formed,together with the head of the engine block, with an opening 20, leadingfrom the casing 13 to the firing cylinder said parts being also formedwith an opening 21, opening from the compression cylinder. into thetransfer valve casing. The valve is normally held closed by a spring 22,hearing between a removable fastening on the end of the valve rod 17 andthe projection 16.

In operation, as so far described, the compression piston, in itsdownward stroke draws in a charge through the inlet valve 9. the similarstroke of the power cylinder being the firing stroke. On the up stroke.the. pistons are of course moving in unison, with the power piston inadvance. The power piston moves the full length of the up stroke toforce out the spent gases, the exhaust valve being held open. During theup stroke of the compression piston, the charge previously drawn in iscompressed. During practically the full compression stroke, the transfervalve is held closed by spring 22, until just before the up stroke ofthe compression piston is completed, the power piston, by starting thedown stroke. overbalances the transfer valve, by the tendency to createa vacuum in the firing cylinder, the transfer valve is opened, and thecharge under full compression, and without the slightest diminution ofthe compression, as the compression piston is still moving upward, isforced into the firing cylinder. Immediately the compression pistonstarts the downward stroke, the tendency toward a vacuum on this sidewith the pressure of the charge on the firing cylinder side of thevalve, together with the power of the spring 22, instantly closes suchvalve. The engine is timed to fire at the particular moment followingthe closing of the transfer valve.

The power of the charge is thus directed against the power piston whenthe crank operated thereby is at the point of most effective leverage,thus producing maximum power from the action.

The cylinders are of substantially the Same cubical area throughouttheir charging spaces, and this is important as a detail of manufacture.The transfer valve is arranged so that the free end of the casingthereof is readily accessible, in order that such valve may be removedfor grinding or other necessary repair or adjustment. The practicallyintegral construction of the end of the transfer valve casing and thatof the exhaust valve, permits the heat, ofthe exhaust valve parts to becommunicated to the mixture passing through the transfer valve with wellunderstood results. If desired, and as preferred, the interior of thetransfer valve casing may be provided with small projections or points,as 23, to more effectively radiate the conducted heat noted.

Having thus described the invention, what is claimed as new, is I 1. Anengine including an associated pair of cylinders of substantially equalcubical contents. pistons in said cylinders, means to which the pistonsare connected for power purposes. one of said pistons being colinectedto said means so as to travel in advance of the other, means foradmitting a charge of gas to the cylinder having the relatively retardedpiston, an incased spring closed valve entirely ineased within theengine, said spring closed valve being entirely controlled in itsopening movement by the suction of the advanced piston for admittingsuch charge following the compression by the retarded piston to theother cylinder as such advanced piston is started on its firing stroke.said valve being entirely controlled during its closing action by itsspring.

2. An engine having a firing cylinder and a compression cylinder, acompression piston in the com ression cylinder, at power piston in thefl ring cylinder, said power piston having a leadover the compressionpiston, a substantially horizontally disposed spring closed transfervalve establishing communication between the cylinders, said transfervalve being entirely inclosed within the engine and controlled entirelyin its movement to open position against the action of its spring by theinitial vacuum of the firing stroke of the power piston.

3. An engine having a compression cylinder with a compression pistontherein, a firing cylinder with a power piston therein, an inlet valvefor the compression cylinder, an exhaust valve for the firing cylinder,a spring closed transfer valve substantially horizontally disposed andentirely incased within the engine and establishing com municationbetween the cylinders, said spring closed transfer valve being closedand held closed against the compression of the compression piston by itsspring and opened entirely by the suction of the firing piston as itstarts its firing stroke.

4.. An engine having a firing cylinder. a compression cylinder, a pistonin each cylinder, an exhaust valve for the firing cylinder, an inletvalve for the compression cylinder, and a spring. closed transfer valveto establish communication between the cylinders. said transfer valvebeing entirely incased within the engine and entirely controlled in itsmovement to open position by the initial suction from the firing pistonand 111 its movement to closed position by its spring, said valve havinga casing in part substantially integral with the casing of the exhaustvalve to utilize heat of the latter for preheating the charge as itenters the firing cylinder.

5. An engine having a firing cylinder, a compression cylinder, a pistonin each cylinder, an exhaust valve for the firing cylinder, the inletend of said transfer valve casing an inlet valve for the compressioncylinder, is readily accessible, said spring closed 10 and a springclosed transfer valve for estransfer valve being entirely controlleddurtablishing communication between the oyling a transfer operation bythe suction of inders, said. valve having a casing integral the firinpiston.

at one end With the casing of the exhaust In testlmony whereof I afix mysignature. valve and extended therefrom toward and at a distance fromthe inlet valve, whereby JAMES 0,, CASADAY.

